President Clinton summoned the House Democratic leadership to the White House this morning for an urgent meeting at which advisers expect him to express regret for his actions regarding Monica S. Lewinsky in an attempt to shore up political support in the face of possible impeachment proceedings.

Clinton rearranged his schedule and directed his staff to contact top congressional Democrats on Monday night after receiving a frank assessment of his difficult position during a three-hour strategy session with advisers. In addition to offering personal contrition, advisers said, the president plans to ask party leaders to stick by him until independent counsel Kenneth W. Starr sends Congress his report on the matter, possibly this week.

"He's mending bridges and they're getting everybody to hold until the report comes out," said a presidential adviser who did not want to be named. "The overall strategy should be, 'Hold your fire.' Anything that anybody does right now will be canceled temporarily by the report."

The decision to reach out to House Democrats underscored the depth of the president's problems in his own party, as more officeholders condemn his behavior. White House strategists want to halt the slide on Capitol Hill, particularly in the congressional chamber empowered by the Constitution to launch impeachment proceedings.

Amid indications that his report is imminent, Starr yesterday rejected a request by Clinton's personal lawyer, David E. Kendall, to review it first. Kendall had asked for a week to examine the report and prepare a reply, but Starr said he had no intention of letting anyone see it before it goes to the House.

"In my view, it is for Congress, the repository of the impeachment power, to decide if and when such information should be provided to your client," Starr wrote Kendall.

Starr allies said yesterday that his office is rushing to finish the report in a matter of days to minimize preemptive attacks by the White House, even though the House does not return to town until today and has not yet determined its procedures for receiving the 300-page-plus document and accompanying appendices. The White House and congressional officials expect the report to detail possible offenses committed by Clinton when he tried to conceal his extramarital relationship with Lewinsky during the Paula Jones sexual harassment lawsuit, possibly including perjury and obstruction of justice.

While senior aides immersed themselves in damage-control discussions, Clinton traveled to Maryland yesterday to discuss his fall policy priorities. At Pine Crest Elementary School in Silver Spring, Clinton made no mention of the Lewinsky controversy but seemed subdued as he touted his education agenda and warned against complacency in domestic policy.

"Sometimes when things are going really, really well for people, they get a little self-indulgent, easily distracted and basically just want to kick back and relax," Clinton told parents and school administrators. Clinton, though, presented himself as preoccupied by the press of official business, not questions of political survival, and stressed that "even on its worst day, this is a very interesting job the American people have given me."

In Congress, the tough words from fellow Democrats continued to rain down on the president. Sen. Barbara Boxer (D-Calif.) took the Senate floor to say she agreed with last week's condemnation of Clinton's conduct by Sen. Joseph I. Lieberman (D-Conn.), including "his understanding of the options that are before this body," which includes a possible censure of the president.

Boxer, whose daughter is married to Hillary Rodham Clinton's younger brother, repeated past statements describing the president's behavior as "wrong" and "indefensible," adding that he should have "taken responsibility much earlier." But Boxer, who faces a tough campaign for reelection this fall, also praised Clinton's economic and budgetary performance.

Sen. Ernest F. Hollings (D-S.C.), who also faces voters in November, had a harsher judgment. "We're fed up," he told the Associated Press. "The behavior, the dishonesty of the president is unacceptable and we'll see with the report what course the Congress will take."

The main focus remained on the House, which returns from summer recess today to face the vexing question of how to handle the first presidential impeachment report ever sent under the independent counsel law. Republican and Democratic leaders are preparing both to haggle over procedures and to plot strategies with their members.

After leaving the 8 a.m. White House meeting, House Minority Leader Richard A. Gephardt (D-Mo.) will go to a 9:30 a.m. session with Speaker Newt Gingrich (R-Ga.), House Majority Leader Richard K. Armey (R-Tex.) and other leaders to discuss how to handle the Starr report.

Democrats warned that they should not be cut out of the decision. "Either we'll be brought into the process as full partners, equals and trusted colleagues or this entire exercise will collapse under the weight of its own partisanship," said Jim Jordan, a spokesman for the Judiciary Committee Democrats. A Republican committee aide said that side is committed to working out differences.

But neither side has figured out within its own ranks how to proceed. Members of both parties are divided on the critical question of whether to release Starr's report publicly once it arrives on Capitol Hill.

Some Democrats are increasingly worried that a vote to keep the report secret would be used against them in the fall campaign. Rep. Tim Roemer (D-Ind.) said he has "not heard a compelling reason to keep it secret. ... I think all of us in Congress are entitled to the information in the report. I think the public is entitled to the report."

But other Democrats feared releasing a report they fear will contain inaccuracies or a skewed version of the facts. "I just don't think it's fair to the president," said Rep. James P. Moran Jr. (D-Va.). "He's going to be accused of enough stuff he's responsible for."

Clinton convened his lawyers and political advisers at the White House on Monday to assess where he stands and develop a strategy for defending himself. Returning to Washington after three weeks of vacation and foreign travel, the president was told his political dilemma in Washington has grown perilous, which he appeared aware of and eager to attack head on, according to a source familiar with the discussion.

Among his strategists, however, there is no consensus on how to proceed. Some advocate a plea-bargain-style approach in which he cuts a deal with Congress for some form of censure, while others suggest preparing for a long, drawn-out fight relying on polls showing that the public does not favor impeachment. One idea that has been floated, although not during Monday's meeting, would be for Clinton to demand that Congress stay in town to deal with the Starr report rather than go home to campaign for the November elections, although several advisers found little appeal in such a tack.

An immediate question facing Clinton's damage-control team is the hiring of a new person to serve as ambassador to Congress during the impeachment hearings that many aides now consider to be virtually inevitable following the delivery of Starr's report.

Some senior political and legal advisers said they had hoped to have the new person on board by this week, but some aides said it now seems less likely they can meet this schedule. There are indications that the White House is having trouble filling the post. Former Watergate prosecutor Richard Ben-Veniste and former deputy White House counsel W. Neil Eggleston both have turned down entreaties to join the staff.

Clinton advisers also have indicated interest in recruiting former Senate majority leader George J. Mitchell (D-Maine), possibly as a counselor in charge of leading the defense against impeachment. Clinton and Mitchell spent time together during last week's trip to Ireland and Northern Ireland, where the former senator served as the president's special negotiator.

Clinton has been calling congressional Democrats to offer regrets and his newly emerging strategy calls for him to continue seeking absolution from members of Congress. But for now at least, there likely will be no more public apologies of the sort he has issued in recent weeks. "I have a feeling all his future apologizing will be in private," said an adviser.

Interviews with others who will be at today's meeting suggested the president will hear mixed messages. "There is really profound disappointment with the president's misconduct and I share it," said Rep. Rosa L. DeLauro (D-Conn.). "I agree with Senator Lieberman's sentiments. This really overshadows the great accomplishments of this administration."

But Rep. Vic Fazio (D-Calif.) said, "People are more concerned about their own personal lives, and their futures. They may be concerned, even angry, but they are not anxious to see him removed from office."

Rep. John Lewis (D-Ga.) agreed, pointing to Clinton's comment in Ireland last Friday that he was "very sorry" about the affair. "I don't know how much more he can say," Lewis said. "I don't want to see him sitting in front of the White House in sackcloth and ashes."